Valve for air-brakes



(No Model.) 2 Sheets-Sheet 1.,

O. W. GREEN.

VALVE FOR AIR BRAKES.

No. 309,845, I Patented Dec. 30, 1884.

W' I TW' ESSES (No Model.) 2 SheetsSheet 2.

O. W. GREEN.- VALVE FOR AIR BRAKES.

No. 309,845. Patented Dec. 30, 18-84.

Tries. V

CHARLES XV. GREEN, OF SORANTON, PENNSYLVANLL VALVE FOR AIR-BRAKES.

SPECIFICATION forming part of Letters Patent No. 309,845, dated December30, 1884.

Application tiled Ju'y '2, I594.

1'0 all whom, it may concern.-

Be it known that I, CHARLES W. Gnnnn. of Scranton, in the county ofLackawanna and State of Pennsylvania, have invented certain new anduseful Improvements in Valves for Air-Brakes; and I do hereby declarethe following to be a full, clear, and exact description of the same,reference being had to the accompanying drawings, forming a part of thisspecification, and to the figures and letters of reference markedthereon.

My present invention relates more especially to that class ofpncnmaticbrake-operating mechanism wherein the air or other elasticfluid being supplied under pressure causes the release of the brakes andthe charging of the reservoir, and by a diminution of pressure in thesupply-pipe a connection is automatically effected between the reservoirand the mechanism controlling the brakes, whereby the latter are causedto be actuated by the compressed air contained within the reservoir; andit consists in certain improvements in the construction and arrangementof 'the actuating-valve and its connections, as

hereinafter more fully described, and pointed out in the claims.

In the accompanying drawings, Figure l is a side elevation, Fig. 2 a topview, and Fig. 3 a transverse section, of a valve mechanism illustratingmy present invention. Fig. at is a side view, partly in section, of thevalve. Fig. 5 is a side "iew illustrating a modified arrangement of theconnecting-tubesx Similar letters of reference in the several figuresindicate the same parts.

The letter A designates one head or side of the cylinder or reservoirwithin which the air is maintained under pressure, and from whence it isdelivered to a brake-actuating mechanism of any well-known form orconstruction adapted for the purpose.

To the head A, and preferably projecting within the cylinder, where itwill be protected from injury or interference, is screwed or otherwisedetachably secured the valve chambcr or casing B, provided with aremovable cap, B, into which latter is secured the end of thesupply-pipe A]. The valve chamber or easing B is preferably constructed0T castiron, and provided with a tubular brass lining, B, within whichworks thevalve 0. Three (No model.)

sets of passages or ports are cast, drilled, or

otherwise formed through the side walls of the casing or chamber 13. Thepassages a. a. and I) I) open into the interior of the reservoir,, andthe passages c c communicate, the former with the brake-operatingmechanism through the pipe (F, and the latter, a, with the atmospherethrough the eduction-pipe c".

To the inner end or head of the casing B is secured the end of a pipe,0, which communicates with the brake mechanism. The pipes ('I and c areby suitable joints and couplings connected to the pipe c through whichlatter the air is conducted to and from the brakeactuating mechanism.

\Vithin the casing B is arranged the double and reversible valve 0. Thisvalve, preferably composed of brass, is composed of the two heads orpistons, C, united by a reduced por tion or stem, 0-. The heads 0 areexact] y alike, each being provided with a peripheral groove, (7, forthe reception of asplit metallic or othersuitable packing-ring, (Z, andwith a countersink or cavity, (7 within which is located a stud or pin,cl, for sustaining the spring d. The valve as thus constructed, whenplaced within its casing B, ready for action, is maintained in itsforward position by the spring (1, as shown in Fig. \Vhen so held, theforward piston 0 laps over and closes the ports a a, and the rear pistoncloses the ports 0 0, thus leaving only the ports I) b uncovered, andopening the passage from the reservoir or cylinder to the brakemechanism.

The several parts being thus arranged and disposed, the first operationis to charge the several cylinders or reservoirs. This is accomplishedin the following manner: The air under pressure, being turned on, isdelivered through the supply-pipe A in front of the valve 0, forcing thelatter back, closing the ports I) I) and opening the ports a c and c c.The air is thus caused to passed through the ports a a into thereservoir, and, the ports Z) I) being closed, it cannot escape, hence iscom pressed and retained within the reservoir, the pressure in thesupply-pipe being maintained so long as the brakes remain off orinactive. If, new, it becomes necessary or advisable to actuate thebrake mechanism, the pressure in the supply-pipe is diminished or thesupply of air cut oil. As soon as this is accomplished the valve, aidedby its spring, will be moved forward, thus again closing the ports a aand c c and opening the ports I) b. As soon as the ports I) b are openedthe compressed air passes into the rear end of the valve-casing, andthence through the pipe 0 to the operating-cylinder, thus causing thebrakes to be ap plied and held in position by the air-pressure withinthe reservoir.

When it is desired to take off or release the brakes, it is onlynecessary to reestablish the pressure in the supply-pipe, when the valvewill again be forced back, thereby closing theports b I), thus cuttingofi' the supply of air from the reservoir to the cylinder,opening theports a a to again charge the reservoir, and uncovering the ports 0 c toopen the exhaust and permit the air to escape from the cylinder into thecasing between the pistons.

O and out through the pipe 0".

The valve mechanism above described eonstitutes a simple, desirable, andeflieient mech anism for automatically effecting the necessaryoperations of the brake mechanism. The casing and its contained valve,being made separate from and applied to the reservoir in the mannerdescribed, can at any time be removed from one cylinder and be appliedto another, or can be taken off, repaired, and returned to its place.The valve-the only moving portionis automatic in its action, and can atany time be removed and replaced by simply unscrewing the cap-platc.Moreover, as both ends of the valve are the same in structure, no skillor special instructions are required for applying it within the casing,as it operates the same in either position; hence all danger from amisplaced valve is entirely avoided.

Among the important advantages gained by the location of the valve andits easing within thereservoir may be mentioned the freedom which issecured against theaccidental putting on of the brakes by air escapingthrough a loose or defective joint or couplin As the eduetion-passages cc are always open when the induction-passages b b are closed, any airwhich might escape into the pipe leading to the brake-operatingmechanism will find a free passage to the-atmosphere through the pipe 0,and when the induction-passages b b are open and-the cduction-passages c0 closed no defect in the joints or connections within the reservoircould prevent the brake mechanism from being positively actuated andapplied. Should the valves, the packing-rings, or the lining of thevalve-casing become worn or otherwise damaged, every facility isafforded for their removal and repair or the substitution of new partswithout necessitating the removal of either the casing or reservoir andwhile both the latter devices remain in place attached to the car.

Having thus described my invention, I claim as new- 1. In combinationwith the head or side of the air-reservoir, the detachable valve-casingand its connecting-pipes, said casing containing the automatic valvemechanism and the removable cap plate, substantially as described.

2. The valvecasing provided with the ports a a, b I), and c 0, arrangedand located, as de scribed, within the reservoir, in combination withthe reversible valve provided, with the reduced stem and duplicatepiston-heads, sub stantially as described.

3. In a brake mechanism such as described, andin combination with thereservoir thereof, the valve-casing, valve, and connecting-pipes.located wholly within and attached to the said reservoir, substantiallyas described.

4. In combination with the ainreservoir and the valve casing or chamberlocated within and secured thereto, as described, the removable liningand reversible valve, and the removable cap-plate applied to the end ofthe valve-casing outside of the air-reservoir, substantially asdescribed.

5. The combination, in a brake mechanism such as described, and with theair-reservoir thereof, of the automatic valve mechanism con sisting of acasing or chamber removably attached to the head and projecting withinthe reservoir, the valve and removable cap-plate, and theconnecting-pipes, also located within the reservoir, substantially asand for the purpose set forth.

6. The combination, with the air-reservoir, of the valve-casing B,threaded into thehead of said reservoir, the cap B, valve 0, ports a a,b b, and c 0, connections 0 0*, c, 0 and A, substantially as described.

0. \V. GREEN.

\Vitnesses:

J. M. POORE, J. E. PAYFAIR.

